Laundry stacker



Nov. 26, 1968 H. J. WEIR 3,412,875

LAUNDRY STACKER Filed Sept. 6, 1967 Fi .1. Mg 3 HENRY JOHN WEIR,

"mung J; HJMgAM United States Patent LAUNDRY STACKER Henry John Weir,The Yetts, Sedbury, Chepstow, Monmouthshire, England Filed Sept. 6,1967, Ser. No. 665,776 Claims priority, application Great Britain, Sept.6, 1966, 39,868/ 66 5 Claims. (Cl. 214-6) ABSTRACT OF THE DISCLOSURE Astacker for stacking laundry articles when they have been folded afterlaundering comprising a table having a smooth upper surface inclined tothe horizontal, on to which surface articles to be stacked are fed; astop which abuts against the lower edge of the table; and means forwithdrawing the table rapidly away from the stop to allow any articlethereon to drop on to a stack beneath the table. For particularly rapidwithdrawal of the table a two-way air ram may be employed in a pneumaticcircuit which allows either side of the ram to be vented.

The invention relates to a stacker for stacking laundry articles whenthey have been folded after laundering.

According to the invention a laundry stacker comprises a table having asmooth upper surface inclined to the horizontal, on to which surfacearticles to be stacked are fed; a stop having a substantially verticalsurface which abuts against the lower edge of said inclined tablesurface; and means for withdrawing the table rapidly away from the stopto allow any article thereon to drop on to a stack beneath the table.

With such an arrangement it is important to achieve as rapid awithdrawal as possible since the more rapid the action the less will bethe effect of any lateral drag on the article and the more accuratelywill the articles be stacked. In order to achieve a particularly rapidwithdrawal the invention contemplates the provision, as means forwithdrawing the table, of a double-acting air ram linked to the table; atwo-way valve to which the two sides of the air ram are coupled in sucha way as would simultaneously connect one side to a source ofpressurised air and the other side to exhaust, or the other side to thesource of pressurised air and the one side to exhaust, in dependence onthe state of the valve; and an intermediate air valve connected inseries between said two-way valve and the side of the air ram which isexhausted on withdrawal of the table, the intermediate valve beingarranged to couple said side to the two-way valve except when the tableis in the position to receive laundry articles, when the intermediatevalve vents said side to exhaust. In this way an inherent disadvantageof a system which utilises merely a two-way valve of the kind describedis overcome. This disadvantage is that there is always a compressed airsupply connected directly to one side of the air ram or the other. Withthe air ram in the extreme position corresponding to the loadingposition of the table the compressed air supply is on the side of theair ram which is to be exhausted when the table is withdrawn. Therefore,on actuation of the two-way valve, it would be necessary, as the tableis withdrawn, to exhaust the compressed air contained in the air ram.With the provision of an intermediate valve as described above it isensured that there is no such compressed air to be exhausted. Thisallows a much more rapid action of the air ram.

Preferably the intermediate valve is situated beneath the table and hasan actuating arm with which the table co-operates at all times exceptwhen it is in the position to receive laundry articles, co-operation ofthe table with the operating arm coupling the air ram through the in-'ice termediate valve to the two-way valve and release of the operatingarm coupling said side of the air ram to exhaust.

Preferably the two-way valve is reversed before the air ram and thetable reach their fully withdrawn positions. This provides a bufferaction for the table as it approaches the limit in the withdrawnposition. The twoway valve is preferably a solenoid operated valve andthe means for reversing the valve com-prises a microswitch mounted to beactuated by the table as it approaches the fully withdrawn position.

The means for actuating the solenoid valve to withdraw the tablepreferably comprises a delay device capable of responding to a timingsignal and adapted to provide a suitable delay after receipt of thetiming signal before actuating the two-way valve. Conveniently, thetiming signals are derived from a folding mechanism preceding thestacker which folds the articles to be stacked.

The invention will further be described with reference to theaccompanying drawings of which:

FIGURE 1 is a schematic elevational view of a laundry stacker inaccordance with the invention;

FIGURE 2 is a pneumatic circuit diagram of the air ram and actuatingvalve of the laundry stacker; and

FIGURE 3 is a circuit diagram of the actuating arrangement for thesolenoid valve.

Referring to FIGURE 1 the laundry stacker comprises a conveyor 1 whichruns in the direction indicated by the arrow and on to which are fedlaundry articles previously folded by a folding machine (not shown). Theconveyor deposits the folded articles on to a table 2 which has anupper, smooth, inclined surface 3. The articles are prevented fromsliding from the surface by a stop bar 4 which abuts against the loweredge of the surface 3.

Table 2 is capable of being withdrawn to a position indicated in brokenline at 2:1 by a double acting air ram 5. A solenoid operated two-wayair valve 6 operates the air ram to withdraw the table on receipt of asignal from a timing device (not shown) which responds to a timingsignal from the folding device and after a predetermined delay issuesthe signal to actuate the air ram. In this way it is ensured that apredetermined time elap-ses after the final folding of the article, thetime being sufficient to allow the article to be fed on to the table 2.

The arrangement is such that the air ram 5 acts to withdraw the tablerapidly away from: stop bar 4 and thereby remove it from beneath thearticle, the article being allowed to drop on to a pile 7 formed beneathtable 3 on a second table 8. After dropping the article the table 2 isreturned to its normal position abutting stop bar 4. A counter 9 isoperated by the table 2 as it is withdrawn and is effective to count thenumber of times the table is withdrawn. After a predetermined count thecounter closes a circuit to operate a further air ram 10 which iseffective to push the stack 7 sideways to the position illustrated at 7awhere an operator can collect the stack. Counter 9 is capable of beingset to operate at any desired count and, for example, may be set tooperate at 20 articles where the articles are relatively large, such aspillowcases, for example, or at 60 articles for table linen, etc.

The side of the air ram 5 which is exhausted on withdrawal of table 2 isconnected to valve 6 through an intermediate valve 11 which is arrangedbeneath table 2 and has an actuating arm 12 operated by contact withtable 2. The operation of this valve will be described more fully withreference to FIGURE 2.

A microswitch 13 is mounted so as to be operated by table 2 when it isapproaching its fully withdrawn position. This microswitch is connectedin circuit so as to reverse the condition of solenoid valve 6 at thistime and thereby provide an air cushion of pressurised air within airram 5 to decelerate and return table 2 at the appropriate time.

FIGURE 2 shows the pneumatic circuit diagram for the operation of airram 5. Solenoid operated valve 6 has two outlets 14 and 15 to atmosphere(exhaust). An inlet 16 is connected to a source of pressurised air '17.The piston of air ram 5 is shown in the position corresponding to theloading position of table 2 shown in full line in FIGURE 1. When thetable 2 is to be withdrawn the piston is moved to the left and theleft-hand side of air ram 5 is thereby exhausted. It will be seen thatthe two sides of air ram 5 are connected to valve 6, the righthand sidedirectly and the left-hand side through the intermediate valve 11. Withthe intermediate valve 11 released, that is, with operating arm 12 freeof table 2, as shown in FIGURES 1 and 2, it is elfective to vent theleft-hand side of ram 5 to atmosphere. Operation of valve 6 applies airunder pressure to the right-hand side of ram 5 and projects the pistonand table 2 leftwards. Initial movement of the table 2 operates valve 11so that the lefthand side of the air ram is then connected to valve 6,still to exhaust. When the table 2 nears its fully withdrawn positionmicroswitch 13 (FIGURE 1) is operated and is effective to reverse valve6 and thereby apply air under pressure to the left-hand side of ram 5and exhaust the right-hand side. This provides a buffering actionagainst movement of the table, arrests the table and returns it to itsloading position. The interlock of the operating circuit for valve 6 issuch that release of microswitch 13 is not effective to again reversethe valve.

It is important to note that without the provision of the intermediatevalve 11 and with direct connection of the left-hand side of ram 5 tovalve 6 the left-hand side of the air ram would be filled withcompressed air until the valve 6 was reversed. Thus it would benecessary to exhaust this compressed air on withdrawal of the table.Therefore, venting the left-hand side of the air ram to atmosphere inthe Way described is effective in speeding "the operation of the air ramand the withdrawal of table 2.

FIGURE 3 is a circuit diagram illustrating the connection of theoperating circuit for solenoid valve 6. Two supply terminals of oppositepolarity are shown at 18 and 19, a relay 20 being connected to terminal18 and through an external switch 21 to terminal 19. Switch 21 is closedby operation of the folding device for the articles when the final foldis made. This energises relay 20 which closes tWo contacts of the relay22 and 23. Contact 22 is a holding contact for relay 20 and contact 23energises a delay device 24. After a predetermined delay correspondingto the time necessary for the article to reach the table 2 after havingbeen folded by the folding device, device 24 closes a contact 25 whichenergises the solenoid 26 of valve 6. Microswitch 13 is connectedbetween contacts 22 and terminal 19 and i effective on actuation bytable 2 to open the holding circuit for relay 20 thereby deenergisingthe relay and de-activating device 24 so as to de-energise relay 26 andreverse valve 6.

I claim:

1. A laundry stacker comprising a table having a smooth upper surfaceinclined to the horizontal, on to which surface articles to be stackedare fed; a stop having a substantially vertical surface which abutsagainst the lower edge of said inclined table surface; and means forWithdrawing the table rapidly away from the stop to allow any articlethereon to drop on to a stack beneath the table and wherein the meansfor withdrawing the table comprises a double-acting air ram linked tothe table; a twoway valve to which the two sides of the air ram arecoupled in such a way as would simultaneously connect one side to asource of pressurised air and the other side to exhaust or the otherside to the source of pressurised air and the one side to exhaust, independence on the state of the valve; and an intermediate air valveconnected in series between said two-way valve and the side of the airram which is exhausted on withdrawal of the table, the intermediatevalve being arranged to couple said side to the two-way valve exceptwhen the table is in the position to receive laundry articles, when theintermediate valve vents said side to exhaust.

2. A laundry stacker as claimed in claim 1 wherein the intermediatevalve is situated beneath the table and has an actuating arm with whichthe table co-operates at all times except when it is in the position toreceive laundry articles, co-operation of the table with the operatingarm coupling the air ram through the intermediate valve to the two-Wayvalve and release of the operating arm coupling said side of the air ramto exhaust.

3. A laundry stacker as claimed in claim 1 wherein reversing means isprovided for reversing the two-way valve before the air ram and thetable reach their fully Withdrawn positions.

4. A laundry stacker as claimed in claim 3 wherein the two-way valve isa solenoid operated valve and the reversing means comprises amicro-switch mounted to be actuated by the table as it approaches itsfully withdrawn position.

5. A laundry stacker as claimed in claim 1 wherein the two-way valve isactuated by means comprising a delay device capable of responding to atiming signal and adapted to provide a suitable delay after receipt ofthe timing signal before actuating the two-way valve.

FOREIGN PATENTS 881,259 11/1961 Great Britain.

GERALD M. FORLENZA, Primary Examiner. R. J. SPAR, Assistant Examiner.

